Motor-controller



W. C. STEVENS. moron CONTROLLER.

APPLICATION FILED SEPT- 8. I917.

UNITED STATES PATENT OFFICE.

WILLIAM C, STEVENS,'OF MILWAUKEE, WISCbNBIN, ASSIGNOB TO THE CUTLEB- HAMMER 'MFG. 00., OFLKILWAUKEE, WISCONSIN, A CORPORATION OF WIS- consm.

To all whom it may conccm:

Be it known that 1, WILLIAM C. S'ravnna,

a citizen of the United States, residing at Milwaukee in the county of Milwaukee and State of useful Im rovements'in Motor-Controllers, of which t e following is a .full, c'lear concise, and exact description, reference being and to the accompanying drawing, forming 0. art of this specification.

is invention relates to improvements in l l torcontrollers. I One of the objects of the invention 18 to fiovide a unitary electromagnetic controller separate sets of contacts to res ctiv complete the motor circuit and e ect accelgration of the motor butsubject to delay in the performance of the latter function under iven motor conditions.

Anothero ject is'to provide a controller .f of the character stated which may he go verncd from a single control station for. starting, accelerating andstopping, and alsofor Inching.

Another object is to provide a controller of the characterstated having a plurality of control windings acting cumulatively'in starting and controllable for opposed ac- --tion thereof'to efl'ect quick disengagement of the main switch contacts forstopping.

Other objects and advantages of the 'invention .will hereinafter appear.

'The accompanying drawing illustrates one embodiment of the invention and the same will now be described, it being understood that the invention is susceptible of embodiment in otheij' forms falling within the scope of the appended claims.

switch arms, said wmdi alined. and each of said syitclmarmlaoonstivIn the drawing, 1

Figure 1 is a front elevation"of the controller; v

Fig. 2 is a side elevation thereof, partly in section, and

Fig. 3 is a diagrammatic view of one circuit arrangement for the controller.

The controller includes a main switch arm 1, carrying a contact 2 to engage a stationary contact 3, an accelerating switch aif'm 4 carrying a contact 5V to engage a stationary contact 6 and common electroma netic control windings 7 and 8 for said bein hx'ially tutinganarmaturethcl Wisconsin, have invented new and w arms 1 and 4 are carried MOTOR-CONTROLLER.

v when... of m g. retest. P t ted Jan. 13, 1920. m sa. am September e, nm. man He. 189,937.

The windings 7 and 8 are mounted upon a core 9 and are provided with a U-shaped ma netic frame to which said core is attac led, said frame being fixed to a suitable spectively carried by posts 12 and 13 ro ecting mm the panel 11 and the switch by a common pivot pin 14 so :ported by and between ears 10 and 10' o the lower extension of the magnet frame (Fig. 1). The swi'clr arm 4,

which is 'll-shaped, is of magnetic material throughout its entire length and is provided at its lower end with a stop lug 4 to abut a non-magnetic plate 15 on the under side of. the magnet frame and at its uppergend with a conical prbjection 4" end of the core 9. Also, the switcharm 4 is provided with a non-magnetic screw 16 extending therethrough, axially of the conicore -9 to'provide an adjustable minimum air gap between said magnetic parts, said screw icing provided with a lock nut 17. The switch arm 1, .on the other hand, comprises a nmgnctic portion 1' and a non-magopposite the -cul projection, to engage the end face of the netic portion 1", the former being interposed between the arm 4, and the core 9 and recessed to receive .the conical projection 4. Further. the arms 1 and 4 are respectively provided with springs 18 and 1!) connecting the same to the panel 11 for bias of 'said arms away from the core 9, thus normallyefi'ecting engagement of the accelerating contacts 5 and 6 and disengagement of the main contacts 2'and 3.

Assuming energizntion of both windings 7 and 8 for cumulative action thereof, the same cause a magnetic flux to traverse both switch arms and such flux is divided between two circuits, one including .he core 9 and extension 10" of the magnet frame and the other including saidcore and extension 10* of the magnet frame. Normally, however, there is an air gap between the arm 1 and extension 10 of the magnet frame and between both arms and the core 9, while on the otherfhand, the arm 4 completes the other magnetic circuit save for the air gap betvgcmsaid arm and; the core. Kccord ingly the greafer of the magnetic flux initially traverses the circuit through the extension 10" of the magnet frame, dividing between arms 1 and l for attraction of both arms to disengage contacts 5 and t) and engage contacts 2 and 25. However, the noumagnetic pontiou 1" of the arm I initially shunts the greater part of the, magnetic flux traversing the extension it)" of the magnet controller insures againstengagement of the mam sw tch contacts until after disengagemeat 0' he accelerating switch contacts.

Upoi. a traction of both arms. as descriocd. the arm 1 engages the core 9 and extension 10* of the magnet frame whereas the screw 16 maintains the arm 4 ina spaced relation with the. core whereby the reluctance of the magnetic circuit through the extension 10 is reduced helow that of the magnetic circuit through the extension 10" and arm 4. In consequence, )artof the magnetic flux rev'iously trarerslng the. arm 4 is shunted t u-ough the arm 1 thereby rendering the arm 4 more sensitive to release. upon a reduction in the attractive force of the two windings. In the controller illustrated the arm 4 is designed to he released upon a prcdetern iined reduction in the current traversing the whaling 7, for iei ngagw meat of the ata'elcrating switch contacts while the main switch contacts are held closed subject to release up'ou dei nergization of both windings or a change. in the circuit. connections thereof for opposed action.

Further. the controller includes auxiliary contacts '20 and 21. the former being carried by the main switch arm 1 and the latter by a post/22 projecting from the panel 11. These auxiliary contacts are normally disengagcd and arranged to be engaged upon attraction of the main switch arm to engage main contacts 2 and 3.

Referring to Fig. 3, the same shows the controller as employed to control the-coir tinnity of circuit of a shunt motor 23 and to control a starting resistance R in series with the motor armature. Further it'shows a. control station comprising a normally closed push button 24 and a normally open push button 25. for the windings of said controller. The shunt lield winding F of the motor is connected direct-l y across the. supply circuit L-L' while, the controller serves to make and break the armature circuit.

The circuit arrangement is such that closure of push hutton switch .25 completes circuit from line L through the motor armatnrc, by conductor '26 through winding) 7, by conductor 27 through said )llsh utton switch, by conductor 28 to line and a cirsuit from line- L by conductor 29 through winding 8 and a resistance r by conductors 30 and 27 to line L. In a word, closure of this switch provides for connection of the whaling 8 directly acro$ the line through resistance 1- and for connection of the winding 7 across the line through the motor armature so that both windings are subjected to substantially the. full line voltage for cumulative action thereof to, attract both switch arms as above described. With these connections it. is, of course. ap arent that the winding 7 should be of so cient resistance to prevent passage of an operating current through the motor armature, and it is to be assumed that the. resistance of the winding 7 is of such value. W on, however. the. windings attract. both s i h arms, the arm 1 completes circuit for an bperating current through the motor armature from line L thron it said armature and the resistance It and t more through said arm 1, contacts-'2 and 3 and conductor 31 to line L. Also, attraction of. the switch arm 1 completes a circuit from the junction of conductoisl and 30 through not'mally'cloeed push botton switch 24, by conductor 32', through auxiliary contacts 21 and 20 to arm 1 which in attracted position is connected to the right hand terminal of resistance R and to line L. .Thus mountingbutton switch the. winding 8 remains connected across the. supply circuit through resistance r while the winding 7 is shunted with the armature resistance R. iugly the winding 7 is subjected to a clecrease. in current as the armature accelerates upon the initial inrush of current, thereby tending to reieaseswitch arm 4 as above described. When switch arm 4 is released it short circuits resistance R and winding 7 by way of conductor 33 and contacts 5 uncl 6 for acceleration of the motor to full speed, but as will be apparent the arm- 4 is held against release until. the motor has accelel'ated to a redetermined le upon the initial inrus i of'enrrent. This provides for maintaining the resistance, R in circuit for a given period. and as will he understood this period may be, of any predetermined duratron.

Further, the circuit arrangement is such that upon opening of push buttton switch 24 the winding 8 is disconnected from line L, while )th windings 8 and 7 are included in a closed loop across the terminals of the motor armature for op )osed action thereof, thn's roviding for qnlc release of the main switci arm to interrupt the circuit of the motor armature.

Still further the circnit arrangement is such that if switch 24 be held,op en, the

release of push Accord- 7 trol-by said motor for timing the accelerating action of said accelerating contacts.

In' combination, a "'motor, a main switch, an accelerating switch operable with said main switch and also independently thereof and common electromagnetic control. means for said switches to effect operation thereof sequentially, said electromagnetic means being associated with'aid motor for timing of the accelerating operation of the latter switch. i

3. In combination, a motor, a main switch, an accelerating switch oper le .with said main switch and also independently thereof and common electromagnetic con-' trol means for said switches including a winding in circuit with said motor, said electromagnetic means providin for operation of said switches sequentia ly and for arrest of the accelerating operation of the latter switch -under given wnditions in the motor circuit.

4. In combination, a motor and a unitary electromagnetic switch having separate'sets of contacts to respectivel complete the circuit of said motor and e. ect acceleration of said motor while its circuit is so completed, said switch having a winding independent of the motor circuit and a w nding incircuit with said'motonf 5.-Incombination, a motor, 'a series resistance, therefor, a main switch, an acceleratin switci and electromagnetic means inclu mg a inding having a circuit to aim t the sen? with said resistance for. effect' ng sequen ial operation of said switches subject to delay in the accelerating opera- 60 means inciudi tion of the latter switch under given condi: tions-in the motor circuit. I

.6. In ,combinatio nn motor, a se 'es resistancetherefor, a main switch, an accelerating s itch and conunon electromagnetic control means for said switches to effect soquentialbperation' thereof and delayed acoelerating, operation of the latter swltch under givenl. conditio said electromagnetic a winding independent of the circuit or said motor and a windi haw ing conn 'one to shunt the same wit said resistance.

7. In combination, a motor/a main switch, an accelerating switch biased to of sai accelerating position and electromagnetic means to move the latter switch away from accelerating position and the former switch to circuit closing position and then release said latter switch'but subject to delay under given motor conditions.

8. In combination, a motor, a series resistance therefor, an accelerating switch biased to shunt said resistance, a main switch, cumulative electromagnet windings for operatin said switches to interrupt the shunt aroun said resistance and comlete the circuit of said motor and means or placing one of said windings in shunt with said resistance for release of said accelerating switch.

9. In combination, a motor, a series resistance therefor, an accelerating switch biased to shunt said resistance a main switch, cumulative electromagnetic windin for operating shunt aroun said resistance and complete the circuit of said motor and meahs for said switches to interrupt t e placing one of-said windings in shunt with normally engaged contacts and normally discn contacts for control of said windings, circuit connectionswhereby the latter cohtacts serve to establish energizing circuits for both windings to efl'ect cumulative action thereof for opening of said accelerating'switch and closure of said main switch circuit connections whereby closure of said main switch establishes a maintainingcircuit for one of said windings. and circuit connections whereby the other of said windings is shunted with said resistance through said normally engaged contacts for subsequent release of said accelerating switch.

11. In combination, a motor, a series resistance therefor, an accelerating switch biased to shunt said resistance, electromaglatter contacts serve to establish energizing circuits for both windings .to efi'ect cumulathis action thereof for opening of said accelerat' switch and closure of said 'main switch circuit connections whereby closure d main switch establishes a maintaining circuit'forfone of said windings and circuit connections whereby the otherof said wind" 'is shunted wit said resistance contacts tor as 5 c ect differential notion thereof for release of said main switch.

12. In a motor controller, in combination, a. main switch biased to open position,

,c'nraccelcrating switch biased to acceleratmg position and common electromagnetic operating means therefor controllable to more the latter switch away from accelerating position and the former switch to closed position and then release said accelerating switch while retaining said main switch in closed position.

13. In a n otor controller, in combination, a main switch biased to open posi 'tion, an accelcratin r switch biased to accelerating position am cumulative electromagncti f windings associated with said switches, sai wmdings serving to move the latter switch away from accelerating position and the former switch to closed sition and said windings being controllab e to release said latter switch and hold said former switch.

14.111 a motor controller, in combination; I

a main switch biased to open position, an accelerating switch biased to closed position and a common operating electromcgnet therefor, each of said switches including a. ma 'netic part providing'an armature for sai electromagnet and said electromagnet having a magnetic frame adapted upon attraction of the m etic switches to divert said accelerating switch a portion of its magnetic flux where: by said accelerating switch will be so itire to release independently of said ma switch. In witness whereof, I have hereunto subscribed my name.

WILLIAM (J. STEVENS;

3 parts of both. 

